We reviewed the cranial MRI and radionuclide cisternograms of four adults w
ith postural headache indicating spontaneous intracranial hypotension (SIH)
. All four underwent clinical and radiological follow-up. MRI showed diffus
e, thin meningeal enhancement; bilateral subdural fluid collections; and mo
rphological abnormalities secondary to "sagging" of the brain. Radionuclide
cisternography revealed direct or indirect signs of leakage of cerebrospin
al fluid (CSF) along the spinal axis, and the symptoms resolved after the l
eak treated by epidural injection of blood at a level indicated by the cist
ernogram. The diffuse meningeal enhancement decreased but persisted on foll
owup MRI, although the patients were asymptomatic. All morphologic abnormal
ities resolved during 3-5 months follow-up.